Robert henry davis



L. A. LEVY. APPARATUS FOR USE WITH HESPIRATORS FOR THE DETECTION 0F SMALL QUANTITIES 0F CARBON MONOXXDE. APPLICATION FILED JULY 5| 1921.

1,414, 1 94. Patented Apr. 25, 1922.

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, LEONARD ANGELO UNITE-D sT-Aias PATENT OFFICE.

LEVY, on cRicKLEwoon, -ENGIQANnAssiGNOE OE ONE-HALE To ROBERT HENRY Davis, OE LONDON, ENGLAND.

' APPARATUS EOEUSE WITH EEsPiEAToEs EOE THE DETECTION OESMALL QUAN- rTITiEsoE CARBON ivioNoXinE.

Specification ef Letters Patent.

Patented Apr. 25, 1922.

Application filed July 5, 1921.V Serial No. 482,625.

(GRANTED UNDER THE PROVISIOITS` 0F THE ACT 0F MARCH 3, 1921, 4 1 STAT. L., 1313.)

To all whom t 'may concerti.:

Be it known thatl, LEONARD ANGELO LEvY, a subject of the Kingo'l: Great Britain, residing at 8l Shoot-up Hill, Cricklewood, Middlesex, England, have invented new and useful Apparatus for Use with Respirators for the Detection of Small Quantities of Carbon Monoxide, (for which l have led an application in Great Britain Feb. 9, 1920, Patentllo. 163,102,), oi' which the following is a specification.

illy invention lrelates to apparatus for use with respirators, for the detection Ot small quantities of carbon-monoxide.

vis will be understood, in the case of respirators which are worn for the purpose oi' protecting the wearers against the effects of carbon-monoxide, when the respirator is approaching exhaustion, it become necessary tor meansto be provided whereby such exhaustion is made known to the wearer, as

.otherwise he would receive 11o-warning and would be subjected to the toxic action oi': the

gas. V

The object of my invention, therefore, is to provide simple and eilicient means for the detection ot small quantities oi the gas, and to this end l provide an appliance through which the air to be breathed passes and which is provided with a reagent, which, on contact with even small quantities of carbon monoxide, generates a small quantity .oi vapour which may be irritant oi lachrymatory, or both. This vapour is preferably iodine, which, by its effects upon the eyes sind nose particularly, and also to a less extent on the throat, gives ample warning to the wearer that his respirator is approaching,- exhaustion. At the same time the apparatus is so constructed that the traces of carbon monoxide which commence to pass are destroyed in the detector, and so rendered innocuous.

lin a suitable arrangement oi" the invention, the inspired air, zitter passing through the respirator, is caused to flow over a layer oi' puinice granules treated with a mixture oi iodine peutoxide and iuming sulphuric acid. This reagent oxidizes any monoxide present to dioxide and liberates odine,

which, by the above mentioned effects, on

the layer of pumice containing` the reagent may be succeeded by a second layer of pumicel granules impregnated with sulphuric acid to keep it dry, a filtering body of suitable material, such as cotton-wool or cellulose .wa-deling being finally added for the purpose `or removing any sulphur' trioxide fumes, ywhich may be evolved.

Carbon monoxide respirators are usually provided with a drying agent so that the .inspired air is in a dry and generally warm A carbon monoxide respirator which functions catalytically may pass a little carbon drying agent, such as pumice granules im-, pregnated with sulphuric acid, which would Vthen form the rst layer of the detector.

monoxide at the commencement oi its operation and also possibly small traces continuously. As it is not advisable that the detector should respond to this passage of gas, we may provide lor holding back or preventing the passage of the iodine vapour which is thusl developed, thisbeing preferan bly eiiected by the provision of a layer of granules of relatively low absorbing value and capable of absorbing a very small quantity of iodine, such, for instance, as inactive wood-charcoal or animal-charcoal or granules composed of alkaline constituents and binding medium. This layer should be placed immediately alter the layer con tainingthe detector reagent.

To enable the invention to be Jfully understood, l will describe it by reference to the accompanying drawing, -in which Figure 1 is a section elevation Oi" a respirator furnished with a. carbon monoxide detector in accordance with the invention, and

Figure 2 is an end elevation thereof.

Figure 3 is an elevation illustrating a modification.

Referring lirst to the construction illustrated in Figures 'l and 2, a indicates the metal canister or casing which is divided transversely into two parts, namely the purifying appliance o and the detector c by means of the transverse partition d. e is an inlet valve Which is fitted to one end of the casing or canister a. and through which the impure air is breathed and f is a valve which is fitted in the partition Z and which controls communication between the'compartments b and c.

g is the` outlet for the purified air, which outlet is in communication with the facepiece or breathing mask.

The purifying chamber Z) is divided by a series of perforated transverse partitions it and 2 into a series of sub-divisions containing, respectively, the drying layer. whichcan be composed of calcium chloride granules and layers /c which eliminate any carbon monoxide present in the air passing through the apparatus. The partition. /L is advantageously made of the curved shape shown in Figure l so as to leave afree space above and around the valve e and to facilitate a'uniform flow of air through the canister.

The compartment c is similarly sub-dr vided by means of transverse partitions Z and m, the sub-divisions being filled, respectively, with a layer a of a substance or mixture, which, on contact With the carbon monoxide oxidizes the latter and liberates iodine. Such substance may, for example,

.be composed of a mixture of iodine pentoxide and filming sulphuric acid. The compartment adjacent to that containing the -mixture ny is lilled with a filter o such, for ex ample, as cotton Wool or cellulose Wadding for the purpose of 'eliminating sulphur trioxide fumes where such are generated.

in Figure 3, is similar to that above de-y scribed with reference to Figures l and 2, and differs therefrom only in the fact that the compartments b and 0 are contained in separate casings or canisters a, al which are connected together by a neck g. This form ofthe apparatus functions in a precisely similar manner to that hereinbefore described.

Claims. f

l. The combination with a respirator of apparatus for the detection of small quantities of carbon monoxide comprising a chamber enclosing a reagent which, on Contact with carbon monoxide, generates a small quantity of irritant or lachrymatory vapour,`

which travels With the inspired atmosphere and by its effect on the wearer indicates the approaching exhaustion of the respirator, substantially as hereinbefore described.

2. A respirator as claimed in claim l, having a Weak absorbent for the irritant vapour generated, substantially as herein described.

LEONARD ANGELO LEvY. 

